the thing with photographs. >> juliette kayyem. our thanks to you. those bomb signatures come off both the exploded and unexploded ordnance in this case. you're going to want to stay with cnn throughout the morning for really the most complete, up-to-date coverage of this terror attack at the boston marathon. ahead this morning, you know, we have the fbi taking the lead in the investigation. raising its mobilization efforts to level one. we're going to tell you what that means. plus we'll have the latest on the search for suspects, it's wide-ranging and what happens. we'll tell you right here. >> major cities like miami, chicago, new york, los angeles, they are all on heightened states of alert this morning. how the attack in boston, how that could affect you in your town today. >> and also, you know, this city has to live, it has to move on. how tough is it going to be for the city of boston and the country to bounce back from this after the marathon, bombings? we're going to have all of that on the state of america psyche coming up next. the one th